[v7,1/4] drivers: hwmon: Add max31760 fan speed controller driver

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index e70d9614b..46ae3c4c4 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1066,6 +1066,18 @@  config SENSORS_MAX31730
 	  This driver can also be built as a module. If so, the module
 	  will be called max31730.
 
+config SENSORS_MAX31760
+	tristate "MAX31760 fan speed controller"
+	depends on I2C
+	select REGMAP_I2C
+	help
+	  Support for the Analog Devices MAX31760 Precision Fan-Speed
+	  Controller. MAX31760 integrates temperature sensing along with
+	  precision PWM fan control.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called max31760.
+
 config SENSORS_MAX6620
 	tristate "Maxim MAX6620 fan controller"
 	depends on I2C
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 007e829d1..1c0fa4dd8 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -140,6 +140,7 @@  obj-$(CONFIG_SENSORS_MAX1668)	+= max1668.o
 obj-$(CONFIG_SENSORS_MAX197)	+= max197.o
 obj-$(CONFIG_SENSORS_MAX31722)	+= max31722.o
 obj-$(CONFIG_SENSORS_MAX31730)	+= max31730.o
+obj-$(CONFIG_SENSORS_MAX31760)  += max31760.o
 obj-$(CONFIG_SENSORS_MAX6620)	+= max6620.o
 obj-$(CONFIG_SENSORS_MAX6621)	+= max6621.o
 obj-$(CONFIG_SENSORS_MAX6639)	+= max6639.o
diff --git a/drivers/hwmon/max31760.c b/drivers/hwmon/max31760.c
new file mode 100644
index 000000000..7a7033e6c
--- /dev/null
+++ b/drivers/hwmon/max31760.c
@@ -0,0 +1,595 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/err.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/i2c.h>
+#include <linux/regmap.h>
+#include <linux/util_macros.h>
+
+#define REG_CR1		0x00
+#define CR1_HYST	BIT(5)
+#define CR1_DRV		GENMASK(4, 3)
+#define CR1_TEMP_SRC	GENMASK(1, 0)
+#define REG_CR2		0x01
+#define CR2_STBY	BIT(7)
+#define CR2_ALERTS	BIT(6)
+#define CR2_DFC		BIT(0)
+#define REG_CR3		0x02
+#define REG_PWMR	0x50
+#define REG_PWMV	0x51
+#define REG_STATUS	0x5A
+#define STATUS_ALARM_CRIT(ch)	BIT(2 + 2 * (ch))
+#define STATUS_ALARM_MAX(ch)	BIT(3 + 2 * (ch))
+#define STATUS_RDFA		BIT(6)
+
+#define REG_TACH(ch)		(0x52 + (ch) * 2)
+#define REG_TEMP_INPUT(ch)	(0x56 + (ch) * 2)
+#define REG_TEMP_MAX(ch)	(0x06 + (ch) * 2)
+#define REG_TEMP_CRIT(ch)	(0x0A + (ch) * 2)
+
+#define TEMP11_FROM_REG(reg)	((reg) / 32 * 125)
+#define TEMP11_TO_REG(val)	(DIV_ROUND_CLOSEST(clamp_val((val), -128000, \
+							     127875), 125) * 32)
+
+#define LUT_SIZE	48
+
+#define REG_LUT(index)		(0x20 + (index))
+
+struct max31760_state {
+	struct regmap *regmap;
+
+	struct lut_attribute {
+		char name[24];
+		struct sensor_device_attribute sda;
+	} lut[LUT_SIZE];
+
+	struct attribute *attrs[LUT_SIZE + 2];
+	struct attribute_group group;
+	const struct attribute_group *groups[2];
+};
+
+static bool max31760_volatile_reg(struct device *dev, unsigned int reg)
+{
+	return reg > 0x50;
+}
+
+static const struct regmap_config regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0x5B,
+	.cache_type = REGCACHE_RBTREE,
+	.volatile_reg = max31760_volatile_reg,
+};
+
+static const int max31760_pwm_freq[] = {33, 150, 1500, 25000};
+
+static int tach_to_rpm(u16 tach)
+{
+	if (tach == 0)
+		tach = 1;
+
+	return 60 * 100000 / tach / 2;
+}
+
+static int max31760_read(struct device *dev, enum hwmon_sensor_types type,
+			 u32 attr, int channel, long *val)
+{
+	struct max31760_state *state = dev_get_drvdata(dev);
+	unsigned int regval;
+	unsigned int reg_temp;
+	s16 temp;
+	u8 reg[2];
+	int ret;
+
+	switch (type) {
+	case hwmon_temp:
+		switch (attr) {
+		case hwmon_temp_fault:
+			ret = regmap_read(state->regmap, REG_STATUS, &regval);
+			if (ret)
+				return ret;
+
+			*val = FIELD_GET(STATUS_RDFA, regval);
+
+			return 0;
+		case hwmon_temp_max_alarm:
+			ret = regmap_read(state->regmap, REG_STATUS, &regval);
+			if (ret)
+				return ret;
+
+			if (channel)
+				*val = FIELD_GET(STATUS_ALARM_MAX(1), regval);
+			else
+				*val = FIELD_GET(STATUS_ALARM_MAX(0), regval);
+
+			return 0;
+		case hwmon_temp_crit_alarm:
+			ret = regmap_read(state->regmap, REG_STATUS, &regval);
+			if (ret)
+				return ret;
+
+			if (channel)
+				*val = FIELD_GET(STATUS_ALARM_CRIT(1), regval);
+			else
+				*val = FIELD_GET(STATUS_ALARM_CRIT(0), regval);
+
+			return 0;
+		case hwmon_temp_input:
+			reg_temp = REG_TEMP_INPUT(channel);
+			break;
+		case hwmon_temp_max:
+			reg_temp = REG_TEMP_MAX(channel);
+			break;
+		case hwmon_temp_crit:
+			reg_temp = REG_TEMP_CRIT(channel);
+			break;
+		default:
+			return -EOPNOTSUPP;
+		}
+
+		ret = regmap_bulk_read(state->regmap, reg_temp, reg, 2);
+		if (ret)
+			return ret;
+
+		temp = (reg[0] << 8) | reg[1];
+
+		*val = TEMP11_FROM_REG(temp);
+
+		return 0;
+	case hwmon_fan:
+		switch (attr) {
+		case hwmon_fan_input:
+			ret = regmap_bulk_read(state->regmap, REG_TACH(channel), reg, 2);
+			if (ret)
+				return ret;
+
+			*val = tach_to_rpm(reg[0] * 256 + reg[1]);
+
+			return 0;
+		case hwmon_fan_fault:
+			ret = regmap_read(state->regmap, REG_STATUS, &regval);
+			if (ret)
+				return ret;
+
+			if (channel)
+				*val = FIELD_GET(BIT(1), regval);
+			else
+				*val = FIELD_GET(BIT(0), regval);
+
+			return 0;
+		case hwmon_fan_enable:
+			ret = regmap_read(state->regmap, REG_CR3, &regval);
+			if (ret)
+				return ret;
+
+			if (channel)
+				*val = FIELD_GET(BIT(1), regval);
+			else
+				*val = FIELD_GET(BIT(0), regval);
+
+			return 0;
+		default:
+			return -EOPNOTSUPP;
+		}
+	case hwmon_pwm:
+		switch (attr) {
+		case hwmon_pwm_input:
+			ret = regmap_read(state->regmap, REG_PWMV, &regval);
+			if (ret)
+				return ret;
+
+			*val = regval;
+
+			return 0;
+		case hwmon_pwm_freq:
+			ret = regmap_read(state->regmap, REG_CR1, &regval);
+			if (ret)
+				return ret;
+
+			regval = FIELD_GET(CR1_DRV, regval);
+			if (regval >= ARRAY_SIZE(max31760_pwm_freq))
+				return -EINVAL;
+
+			*val = max31760_pwm_freq[regval];
+
+			return 0;
+		case hwmon_pwm_enable:
+			ret = regmap_read(state->regmap, REG_CR2, &regval);
+			if (ret)
+				return ret;
+
+			*val = 2 - FIELD_GET(CR2_DFC, regval);
+
+			return 0;
+		case hwmon_pwm_auto_channels_temp:
+			ret = regmap_read(state->regmap, REG_CR1, &regval);
+			if (ret)
+				return ret;
+
+			switch (FIELD_GET(CR1_TEMP_SRC, regval)) {
+			case 0:
+				*val = 2;
+				break;
+			case 1:
+				*val = 1;
+				break;
+			case 2:
+			case 3:
+				*val = 3;
+				break;
+			default:
+				return -EINVAL;
+			}
+
+			return 0;
+		default:
+			return -EOPNOTSUPP;
+		}
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int max31760_write(struct device *dev, enum hwmon_sensor_types type,
+			  u32 attr, int channel, long val)
+{
+	struct max31760_state *state = dev_get_drvdata(dev);
+	unsigned int pwm_index;
+	unsigned int reg_temp;
+	int temp;
+	u8 reg_val[2];
+
+	switch (type) {
+	case hwmon_temp:
+		switch (attr) {
+		case hwmon_temp_max:
+			reg_temp = REG_TEMP_MAX(channel);
+			break;
+		case hwmon_temp_crit:
+			reg_temp = REG_TEMP_CRIT(channel);
+			break;
+		default:
+			return -EOPNOTSUPP;
+		}
+
+		temp = TEMP11_TO_REG(val);
+		reg_val[0] = temp >> 8;
+		reg_val[1] = temp & 0xFF;
+
+		return regmap_bulk_write(state->regmap, reg_temp, reg_val, 2);
+	case hwmon_fan:
+		switch (attr) {
+		case hwmon_fan_enable:
+			if (val == 0)
+				return regmap_clear_bits(state->regmap, REG_CR3, BIT(channel));
+
+			if (val == 1)
+				return regmap_set_bits(state->regmap, REG_CR3, BIT(channel));
+
+			return -EOPNOTSUPP;
+		default:
+			return -EOPNOTSUPP;
+		}
+	case hwmon_pwm:
+		switch (attr) {
+		case hwmon_pwm_input:
+			if (val < 0 || val > 255)
+				return -EINVAL;
+
+			return regmap_write(state->regmap, REG_PWMR, val);
+		case hwmon_pwm_enable:
+			if (val == 1)
+				return regmap_set_bits(state->regmap, REG_CR2, CR2_DFC);
+
+			if (val == 2)
+				return regmap_clear_bits(state->regmap, REG_CR2, CR2_DFC);
+
+			return -EOPNOTSUPP;
+		case hwmon_pwm_freq:
+			pwm_index = find_closest(val, max31760_pwm_freq,
+						 ARRAY_SIZE(max31760_pwm_freq));
+
+			return regmap_update_bits(state->regmap,
+						  REG_CR1, CR1_DRV,
+						  FIELD_PREP(CR1_DRV, pwm_index));
+		case hwmon_pwm_auto_channels_temp:
+			switch (val) {
+			case 1:
+				break;
+			case 2:
+				val = 0;
+				break;
+			case 3:
+				val = 2;
+				break;
+			default:
+				return -EINVAL;
+			}
+
+			return regmap_update_bits(state->regmap, REG_CR1, CR1_TEMP_SRC, val);
+		default:
+			return -EOPNOTSUPP;
+		}
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static const struct hwmon_channel_info *max31760_info[] = {
+	HWMON_CHANNEL_INFO(chip,
+			   HWMON_C_REGISTER_TZ),
+	HWMON_CHANNEL_INFO(fan,
+			   HWMON_F_INPUT | HWMON_F_FAULT | HWMON_F_ENABLE,
+			   HWMON_F_INPUT | HWMON_F_FAULT | HWMON_F_ENABLE),
+	HWMON_CHANNEL_INFO(temp,
+			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT | HWMON_T_FAULT |
+			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_LABEL,
+			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
+			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_LABEL),
+	HWMON_CHANNEL_INFO(pwm,
+			   HWMON_PWM_ENABLE | HWMON_PWM_FREQ | HWMON_PWM_INPUT |
+			   HWMON_PWM_AUTO_CHANNELS_TEMP),
+	NULL
+};
+
+static umode_t max31760_is_visible(const void *data,
+				   enum hwmon_sensor_types type,
+				   u32 attr, int channel)
+{
+	switch (type) {
+	case hwmon_temp:
+		switch (attr) {
+		case hwmon_temp_input:
+		case hwmon_temp_max_alarm:
+		case hwmon_temp_crit_alarm:
+		case hwmon_temp_fault:
+		case hwmon_temp_label:
+			return 0444;
+		case hwmon_temp_max:
+		case hwmon_temp_crit:
+			return 0644;
+		default:
+			return 0;
+		}
+	case hwmon_fan:
+		switch (attr) {
+		case hwmon_fan_input:
+		case hwmon_fan_fault:
+			return 0444;
+		case hwmon_fan_enable:
+			return 0644;
+		default:
+			return 0;
+		}
+	case hwmon_pwm:
+		switch (attr) {
+		case hwmon_pwm_enable:
+		case hwmon_pwm_input:
+		case hwmon_pwm_freq:
+		case hwmon_pwm_auto_channels_temp:
+			return 0644;
+		default:
+			return 0;
+		}
+	default:
+		return 0;
+	}
+}
+
+static int max31760_read_string(struct device *dev,
+				enum hwmon_sensor_types type,
+				u32 attr, int channel, const char **str)
+{
+	switch (type) {
+	case hwmon_temp:
+		if (attr != hwmon_temp_label)
+			return -EOPNOTSUPP;
+
+		*str = channel ? "local" : "remote";
+
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static const struct hwmon_ops max31760_hwmon_ops = {
+	.is_visible = max31760_is_visible,
+	.read = max31760_read,
+	.write = max31760_write,
+	.read_string = max31760_read_string
+};
+
+static const struct hwmon_chip_info max31760_chip_info = {
+	.ops = &max31760_hwmon_ops,
+	.info = max31760_info,
+};
+
+static ssize_t lut_show(struct device *dev,
+			struct device_attribute *devattr, char *buf)
+{
+	struct sensor_device_attribute *sda = to_sensor_dev_attr(devattr);
+	struct max31760_state *state = dev_get_drvdata(dev);
+	int ret;
+	unsigned int regval;
+
+	ret = regmap_read(state->regmap, REG_LUT(sda->index), &regval);
+	if (ret)
+		return ret;
+
+	return sysfs_emit(buf, "%d\n", regval);
+}
+
+static ssize_t lut_store(struct device *dev,
+			 struct device_attribute *devattr,
+			 const char *buf, size_t count)
+{
+	struct sensor_device_attribute *sda = to_sensor_dev_attr(devattr);
+	struct max31760_state *state = dev_get_drvdata(dev);
+	int ret;
+	u8 pwm;
+
+	ret = kstrtou8(buf, 10, &pwm);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(state->regmap, REG_LUT(sda->index), pwm);
+	if (ret)
+		return ret;
+
+	return count;
+}
+
+static ssize_t pwm1_auto_point_temp_hyst_show(struct device *dev,
+					      struct device_attribute *attr,
+					      char *buf)
+{
+	struct max31760_state *state = dev_get_drvdata(dev);
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read(state->regmap, REG_CR1, &regval);
+	if (ret)
+		return ret;
+
+	return sysfs_emit(buf, "%d\n", (1 + (int)FIELD_GET(CR1_HYST, regval)) * 2000);
+}
+
+static ssize_t pwm1_auto_point_temp_hyst_store(struct device *dev,
+					       struct device_attribute *attr,
+					       const char *buf,
+					       size_t count)
+{
+	struct max31760_state *state = dev_get_drvdata(dev);
+	unsigned int hyst;
+	int ret;
+
+	ret = kstrtou32(buf, 10, &hyst);
+	if (ret)
+		return ret;
+
+	if (hyst < 3000)
+		ret = regmap_clear_bits(state->regmap, REG_CR1, CR1_HYST);
+	else
+		ret = regmap_set_bits(state->regmap, REG_CR1, CR1_HYST);
+
+	if (ret)
+		return ret;
+
+	return count;
+}
+
+static DEVICE_ATTR_RW(pwm1_auto_point_temp_hyst);
+
+static void max31760_create_lut_nodes(struct max31760_state *state)
+{
+	int i;
+	struct sensor_device_attribute *sda;
+	struct lut_attribute *lut;
+
+	for (i = 0; i < LUT_SIZE; ++i) {
+		lut = &state->lut[i];
+		sda = &lut->sda;
+
+		snprintf(lut->name, sizeof(lut->name),
+			 "pwm1_auto_point%d_pwm", i + 1);
+
+		sda->dev_attr.attr.mode = 0644;
+		sda->index = i;
+		sda->dev_attr.show = lut_show;
+		sda->dev_attr.store = lut_store;
+		sda->dev_attr.attr.name = lut->name;
+
+		sysfs_attr_init(&sda->dev_attr.attr);
+
+		state->attrs[i] = &sda->dev_attr.attr;
+	}
+
+	state->attrs[i] = &dev_attr_pwm1_auto_point_temp_hyst.attr;
+
+	state->group.attrs = state->attrs;
+	state->groups[0] = &state->group;
+}
+
+static int max31760_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct max31760_state *state;
+	struct device *hwmon_dev;
+	int ret;
+
+	state = devm_kzalloc(dev, sizeof(struct max31760_state), GFP_KERNEL);
+	if (!state)
+		return -ENOMEM;
+
+	state->regmap = devm_regmap_init_i2c(client, &regmap_config);
+	if (IS_ERR(state->regmap))
+		return dev_err_probe(dev,
+				     PTR_ERR(state->regmap),
+				     "regmap initialization failed\n");
+
+	dev_set_drvdata(dev, state);
+
+	/* Set alert output to comparator mode */
+	ret = regmap_set_bits(state->regmap, REG_CR2, CR2_ALERTS);
+	if (ret)
+		return dev_err_probe(dev, ret, "cannot write register\n");
+
+	max31760_create_lut_nodes(state);
+
+	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
+							 state,
+							 &max31760_chip_info,
+							 state->groups);
+
+	return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static const struct of_device_id max31760_of_match[] = {
+	{.compatible = "adi,max31760"},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, max31760_of_match);
+
+static const struct i2c_device_id max31760_id[] = {
+	{"max31760"},
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, max31760_id);
+
+static int __maybe_unused max31760_suspend(struct device *dev)
+{
+	struct max31760_state *state = dev_get_drvdata(dev);
+
+	return regmap_set_bits(state->regmap, REG_CR2, CR2_STBY);
+}
+
+static int __maybe_unused max31760_resume(struct device *dev)
+{
+	struct max31760_state *state = dev_get_drvdata(dev);
+
+	return regmap_clear_bits(state->regmap, REG_CR2, CR2_STBY);
+}
+
+static SIMPLE_DEV_PM_OPS(max31760_pm_ops, max31760_suspend, max31760_resume);
+
+static struct i2c_driver max31760_driver = {
+	.class		= I2C_CLASS_HWMON,
+	.driver = {
+		.name	= "max31760",
+		.of_match_table = of_match_ptr(max31760_of_match),
+		.pm = pm_ptr(&max31760_pm_ops)
+	},
+	.probe_new	= max31760_probe,
+	.id_table	= max31760_id
+};
+module_i2c_driver(max31760_driver);
+
+MODULE_AUTHOR("Ibrahim Tilki <Ibrahim.Tilki@analog.com>");
+MODULE_DESCRIPTION("Analog Devices MAX31760 Fan Speed Controller");
+MODULE_SOFTDEP("pre: regmap_i2c");
+MODULE_VERSION("1.0");
+MODULE_LICENSE("GPL");